Field of the Invention
The present invention relates to a back light unit for an outside mirror of a vehicle. More particularly, it relates to a back light unit for an outside mirror of a vehicle for optimizing a light-emitting structure of LED of the outside mirror to improve visibility of a driver.
Description of Related Art
A blind spot detection (BSD) system of a vehicle is a rear lateral side alarming apparatus for detecting an obstacle approaching a blind spot of a rear lateral side of the vehicle and for providing information about the approaching obstacle to a driver during the traveling.
An existing BSD system usually includes a BSD module (or an indicator module) installed in the outside mirror of a vehicle. The BSD module is attached to a rear side of glass on which an indicator icon is etched.
As illustrated in FIG. 1, an existing BSD module includes an LED 30 and a reflector 40 that are mounted on a printed circuit board (PCB) 20 and is attached to a rear side of glass 50 using a double-sided tape and a glass holder.
The BSD module provides an alarm that an obstacle approaches to a driver such that light is emitted from the activated LED when an obstacle approaching the rear lateral side of a vehicle is detected, and is reflected by the reflector 40 and transmits indirectly the indicator icon etched on the mirror surface to emit the light outside the glass.
However, since the existing BSD module reflects the light from the LED using the reflector to emit the light through the etched portion of the glass, the existing BSD module has a limit to make a uniform distribution and brightness of light.
Due to the limit of the existing BSD module, non-uniform distribution of light by the outside mirror occurs continuously and the visibility of a driver is inferior at night.
If imported goods are used to solve the above-mentioned problem, costs increase and thus there is a limit to apply all kinds of vehicles.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.